Spark plugs gap 1mm. 1.1mm make any diff?
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Feeler gauges are extremely cheap. You should replace them once a year, too. There will not be a significant difference. Maybe just fuel consumption
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1 mm is about .040" and 1.1 mm is about .044", so you are talking about a difference of .004". When plugs fire, a little of the center electrode wears away with each spark. Because of this, over time the gap of the plug will increase slightly. As the gap increases, the spark needs to be at a slightly higher voltager to jump the gap. This makes the coil (either a seperate coil or coil pack) work harder. The harder the coil(s) work, the sooner they will fail. With turbo cars, the higher the boost, the easier it is for the boost to cause a misfire with wider gaps. So, is .004" going to make a difference? Probably not under most normal conditions, but you do want to get it right, and even a little on the low side is better. Auto parts store in the US sell these round keychain spark plug tools for around $1.00. You just fit it into the gap and rotate it until it's snug and read the guage. You can open the gap with it, or tap the center electrode to close the gap. Plugs with multiple center electrodes or surface gap plugs cannot be adjusted. Don't trust "out of the box" or factory settings unless the threaded end of the plug has the round cardboard protector on it... Ron
They are a cheap serviceable part so why not I guess. Agree, I should have addressed the pinging (a few years) before I just didnt realise it may have been the plugs. I need to buy a tool to reach down there as my spanner gizmo is too short oh & a feeler gauge too.
It will be interesting what shape they are in & the gap of the old plugs.
Last time I had a dealer change the plugs & they charged $120 labour & parts.
Cheers M.
It will be interesting what shape they are in & the gap of the old plugs.
Last time I had a dealer change the plugs & they charged $120 labour & parts.
Cheers M.
Hi guys,
Ocuro, just checked & sadly we dont get that in Oz. But we do have a fine looking screwdriver with jack & brace lol.
Busaboy, apparently over gapped plugs can cause a ping from what Ive read. It will be interesting to see if this fixes the problem which seems to occur on very hot days. The fuel should be OK I always run the correct grades.
Cheers M.
Ocuro, just checked & sadly we dont get that in Oz. But we do have a fine looking screwdriver with jack & brace lol.
Busaboy, apparently over gapped plugs can cause a ping from what Ive read. It will be interesting to see if this fixes the problem which seems to occur on very hot days. The fuel should be OK I always run the correct grades.
Cheers M.
Bad plugs will not typically cause pinging. Too high a heat range on the plugs can cause pinging as well as low octane fuel.
John
Wow. Seven years into owning my SAAB I finally learn what that thing is for.
At least it only took me six months to find the seat front pockets.
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0.035 in is about 0.889 mm, that would be a little undergapped. 0.04 in would be about 1.016 mm which is ever so slightly overgapped. I ussually gap mine when new to about 0.038 in which is about 0.96 mm. 1 mm is 0.03937 in
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CM is correct that the wider the gap, the easier high boost will cause misfires, and a smaller gap will all but eliminate it. The Saab recommended gap is for a stock engine with stock boost... Ron
Wow what a difference !!!!!!!!!!!!!!!!! Smooth. As. Silk.
I thought it drove pretty well & the fuel economy was good. But talk about smooth now. The difference with the new plugs & oil is very noticeable.
The 4y/o + old plugs were pitted & the gaps were all over the place (no idea how) but otherwise seemed OK. The biggest gap on the old plugs was 1.7mm & the smallest was 0.7mm instead of the all being 1mm.
Man, its just like falling in love all over.
Cheers M.
I thought it drove pretty well & the fuel economy was good. But talk about smooth now. The difference with the new plugs & oil is very noticeable.
The 4y/o + old plugs were pitted & the gaps were all over the place (no idea how) but otherwise seemed OK. The biggest gap on the old plugs was 1.7mm & the smallest was 0.7mm instead of the all being 1mm.
Man, its just like falling in love all over.
Cheers M.
http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp
I love these pictures. These kinds of photos have been around a long time and available in many auto manuals and basic car care guides but spark plugs really have not changed much over the years.
I love these pictures. These kinds of photos have been around a long time and available in many auto manuals and basic car care guides but spark plugs really have not changed much over the years.
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